Abrading apparatus



June 7, 1938. E 0, HAMREN 2,119,812 n ABRADI NG APPARATUS Filed May 14,1936 Fig .U F4' g. Ji

Patented June 7, 1938 Eric 0. Hamren, Hagerstown, Md., assigner toPangborn Corporation, Hagerstown, Md., a

' ,corporation \of Maryland Application May 14, 1936, Serial No. 79,788

18 Claims.

This invention relates to abrading apparatus and more particularly tomechanical apparatus for propelling abrasives at abrading velocities.

Abrasive throwing wheels having bladed rotors have been known in the artfor many years, and although they are now going into rather wide usethey are open to the objection that valuable time is lost changingblades. The blades of abrasive propelling rotors must be made removable,

so that they may be replaced when they have worn out, and yet must beheld so securely that they will resist the tremendous centrifugal forceexerted when the wheel is operating. In the co-pending application ofWalter L. Keefer, Se-

rial No. 79,559, iiled May 13, 1936, there is disclosed a threadedlocking assembly, which facilitates blade removal and replacement, andit is the purpose of this invention to provide locking assemblies whichare of a somewhat different character and which possess certainadvantages over those shown in the Keefer application.

It is a primary object of this invention to provide novel vabradingmachine blade locking assemblies that securely hold the blades in placeand yet permitthem to be removed and replaced in a minimum of time.

It is a further important object of the invention to provide a novelblade assembly for abrading machines that will hold all oi the bladessecurely in place while the machine is operating, will permit easy andrapid removal and replacement of the blades when they wear out and whichwill also permit Vthe bladesto be removed and replaced in the machine ina different relatlonship to present different surfaces to the abrasivewhen certain of their surfaces have become worn.

A further object is to provide, in an abrading machine having a bladedrotor for propelling the n abrasive, a novel blade mounting assemblywhich will securelyholdthe blades in place and will not work looseduring operation of the machine, involves no threaded or complicatedparts to be jammed with abrasive, and which will permit the blades to bequickly and easily removed from the rotor. 4

Further objects of the invention will become apparent as thespeciication proceeds in connection with the annexed drawing. and fromthe appended claims.

In the drawing:

Figure 1 is a side elevational view of an abrasive propelling rotorequipped with the blade u assembly of this invention, with parts thereofbroken away in order to more cleany illustrate thestructure involved.Figure 2 is a fragmentalview looking at the wheel of Figure 1 from theright-hand end yoi' ing part of my invention. 15

Figure 6 is a sectional view takenJ on line 6 9 of Figure 5.

Figure '7 is a view similar to Figure 5, but illus,- trates a stillfurther form of blade locking assembly of theinvention. .20

Figure 8 is a sectional view on line 8-l of Figure '7, but illustratesthe screw in elevation.

Figures 9, v10, Il and 12 are views siniilaritoy Figure 7, butillustrate somewhat different forms V of the invention. 25 Withcontinued reference to the drawing, wherein like reference charactershave been employed to designate likeparts throughout the several viewsthereof, the rotor is .designated as R, and it is rigidly secured to ashaft il). Shaft-,30

rotor to define a central abrasive admitting space 35 in which anabrasive feeding device F is rotat ably or stationarily supported,depending upon the type of discharge desired.

The feed device illustrated is substantially thev same as that shown inthe copending applica- 40 tion of William A. Rosenberger and Walter L.Keefer, Serial No. 726,188, and it effects direc. tional discharge ofthe abrasive thrown from the wheel, but it is yto be understood that thev invention is not limited to a particular feeding device but may beapplied to any type of 'abrading machine. For instance, feeding devicevF may assume the form of apipe or a chute for dumping the abrasive intothe central space and effecting a three hundred and sixty degreesdlscharge of the abrasive. Also, blades B have been shown as four innumber, but it is to be understo'od that theinventionl is applicable torotors-` having more or less than four blades.

, Secured to the face of rotor R, by a plurality e5 of countersunkscrews I I, arefour symmetrically arranged plates I2. The radial edgesof plates I2 are provided with bevelled faces I3, and the adjacent edgesof each pair of plates define a dove-tail groove I4, as seen in Figure3.

Blades B are provided with correspondingly dove-tail shaped bases to fitin grooves I4, and have inclined faces I5 cooperating with walls I3 ofplates I2. The inclined faces `I5 of blades B merge into abrasivepropelling surfaces I6 provided on eacnl side of the blade. As seen inFigure 1, inclined faces I5 merge with plates I2 in a region spaced fromtheir propelling surfaces IB, with the result that the abrasive movingoutwardly over surfaces I6 is maintained out of abrading contact withplates I2, which are permanent parts of the machine. 'I'lie free edgesof blades B are each provided with a flange or ridge |'I to confine theoutwardly moving abrasive to surfaces I6.

The blades are accordingly mounted for gulded movement toward and awayfrom the axis of the rotor, and although grooves I4, which constitutethe guideways, are shown as being disposed substantially radially, it isto be understood that they may be inclined forwardly or rearwardly withrespect to the direction of rotation if desired without departing fromthe spirit of the invention. b

'I'he preferred form of locking assembly employed for restraining bladesB against outward movement is shown in Figures 1, 2, 3 and 4, and withcontinued reference to these figures, the outer end of each plate I2 isprovided with a recess |3 and a wall I9 disposed parallel to the axis ofrotation of the rotor. As seen in Figure 2, recesses I8 and walls I9cooperate to provide a generally T-shaped recess. Fitting in each recessis a T-shaped locking member or "key 2|, against which the blades areadapted to .abut as shown in Figure 2.

Although the friction set up between the parts as the result of theblades tending to move outwardly in response to centrifugal force, Ipreferably employ, as a safety feature, a positive lock for the keymembers 2|. As seen in Figure 4, each blade B is preferably providedwith a recess defining a shoulder 22 which is adapted to embrace theouter side of the key when it is disposed in locking position. Blades Bare removed from the rotor by tapping them lightly with a hammer so asto move' them inwardly sumciently far to allow keys 2| to be slid pastshoulder 22. In order to facilitate removal of the keys when the bladeshave been moved inwardly as just described each key is provided with arecess 23 in which a screw driver or other tool may be inserted to prythe keys loose. 'I'he inner end of each blade B is also provided with arecess defining a shoulder 22 so as to permit the blades to be removedand reversed.

It is accordingly seen that I have provided a simple effective lockingmeans for the blade, not involving any screw-threaded or other closelyiltting parts and yet which may be readily removed to permit bladeremoval and replacement.

When a new blade is slid inwardly in groove I4, it is slid slightly pastthe position shown in Figure 4, so that keys 2| may be easily slid intoplace to bridge the open end of the slot. After this has been effected,blades B may be slid out wardly to lock keys 2| in position, but ifdesired the wheel may be merely started as centrifugal force will movethe blades out into cooperating engagement with the keys as soon as therotor is started. The inherent friction present between blades B andtheir guides may be relied upon to restrain them against inward movementwhen the rotor is subsequently stopped, but if desired spring means,taking the form of a spilt resilient ring, encircling feed device F andengaging the inner ends of the blades, may be used.

With the wheel rotating in the direction indicated in Figure 2, theabrasive is picked up by and discharged from the counter-clockwisesurfaces IB of blades B. By reason of the symmetrical design of blades Bit is possible to remove the blades when they have become partially wornand reverse them end-for-end and thereby bring a new propelling surfaceinto cooperation with the abrasive. The worn surface is accordinglyplaced on the clockwise side of cach blade. When the new surface hasbecome worn the blades are of course discarded.

In Figure 5 there is shown a somewhat modifledform of locking assemblyand it assumes the form of a locking member 3| extending through anopening 32 in rotor R, the latter preferably having ears providedthereon adjacent opening 32 in order that the general diameter of therotor may be maintained. Locking member 3| is of generally cylindricalform and is provided with a head 33 and an unthreaded shank.

As seen in Figure 6, head 33 is square and one of its flat sidespreferably engages blade B behind shoulder 22. As pointed out inconnectionV with the first form of the invention', non-shouldered bladesmay be used. Plates I2a are preferably cut away to provide recesses 35,which afford working spaces adjacent heads 33 of member 3|. Member 3|may be provided with a round head if desired, but it is preferably ofsquare or hex shape as this type of member may be secured at low cost.

It is apparent that by moving blades B slightly inwardly from theposition shown in Figure 5, member 3| may be readily removed from themachine and the blades removed from rotor R by sliding them out ofguideways I4. The assembly operation is performed in the reverse order.It is apparent that as members 3| are unthreaded they cannot be affectedby straying abrasive and if they should stick they may be pushed outeither by a punch applied to the left hand end of the bolt or by pryingunder head 33 with a screw driver or the like.

In view of the fact square or hex head bolts may be purchased at lowcost I may if desired employ them instead of the unthreaded membersshown. In such event holes 32 would of course be made of larger diameterthan the threaded portion in order that the screws may freely slidetherein.

In Figures '7 and 8, I have illustrated a further modification of theinvention wherein rotor R is provided with a bore 4I provided with acommunicating keyway-like passage 42. A counterbore 43 is also formed inrotor R adjacent bore 4I. A locking member 44 is disposed in bore 4I andis provided with a radially extending spline or tooth 45 and a squarehead 43.

As seen in Figure 7, member 44 is restrained against movement to theleft by engagement of tooth 45 with the bottom of counterbore 43 and itis restrained against movement toward the right by engagement withblades B. It is apparent that by reason of the shoulder formed onmembers by heads 46 it is unnecessary to employ a shoulder 22 on bladeB.

When it is desired to remove blade B, the latter is pushed inwardly aslight distance, member 44 is rotated through 180 degrees oruntil tooth45 is aligned with passageway 42, by grasping head 46 with a suitabletool. Member 44 may then be slid to the left as tooth 45 will slidewithin passageway 42.. The locking member may then be completely removedfrom the device if desired, but it is of course only necessary to moveit a distance approximately equal to the height of head 46 in order toremove the blade from the machine. When the parts are disposed in thelocked position illustrated in Figure 1, it is apparent that theengagement of blades B and one of the flat sides of head 45 positivelyrestrains member 44 against angular movement about its axis andtherefore prevents the latter from working into its unlocking position.

In the form of invention shown in Figure 9, a

2o plug-like member 5| is preferably pipe-threaded into rotor R and isprovided with an internal hexagon-walled socket 52 so that it may beoperated by a suitable hex wrench. Member 5| is provided with a' headhaving a tapered wall 53 and the outer edge of blade B is preferablyprovided with a similarly tapered surface 54. When the parts aredisposed in the position shown in Figure 9, it is apparent thatengagement of tapered surface 54 with tapered surface 53 of the plughead prevents the plug head from working into its released position.Although member 5| is threaded the thread is of the pipe variety andhence is self-cleansing.

When it is desiredto remove the blade it may be driven inwardly topermit plug 5| to be unscrewed, but if desired socket may need only beengaged by a wrench, and the plug unscrewed because during thisoperation tapered surface 53 of the plug will, in moving to the left,tend to push or cam blade B into slightly inward position and permit theplug to move into released position.

If desired, plug 5| may assume the form of a cylindrical unthreadedmember and be provided with a stop for preventing it from moving to theright in response to the centrifugally induced forces applied to taperedsurface 53 by blades B.

In Figure 10, I have illustrated a locking assembly of this character.Plug 5Ia is provided with a shoulder portion 56V seating in acounterbore 58 in rotor R. It is therefore apparent that the tendency ofblade B, to push plug 5|a to the right, in response to application offorces to tapered surface 53a, will merely pull shoulder portion 56 intoengagement with the bottom of counterbore 58.

In Figures 11 and 12, I have illustrated blade locking assemblies whichare held in place by a set screw.

In Figure 11 a locking member 6|, having a circumferential groove 62, isslidably mounted in a bore 63 in rotor R. Member 6| is provided with areduced portion 65 which provides an abutment for blades B. A block ofrubber 66 is mounted in a bore 61 and is adapted to be forced intogroove (i2-the blade locking position-shown in Figure 1l by a set screw68, which preferably is provided with pipe threads, so that it willundergo a self-locking action when it is turned home. It is apparentthat set screw 68, when unscrewed, will relieve the block 61 and willpermit member 6| to be removed, thereby permitting blade removal andreplacement.

In Figure 12, a somewhat similar structure is internal pressure inrubber shown but bore 63 is larger and a'rubber bushing 63 is disposedbetween it and member 6Ia.

Set screw 68a is provided withl a plunger portion 1|, which as seen inFigure 12, will deform bushmay be duplicated on each disc.

The term guideway, as employed in the appended claims, is used in itsbroader sense and is intended to cover a partial or incomplete guideway.For instance the guideway provided by plates |2 might be discontinuous,that is, short guiding portions may be provided adjacent their inner andcuter end s and yet the blades would still be mounted for a small degreeof sliding movement. t

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to b'e considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and rangeof'equivalency of the claims are therefore intended to be embracedtherein.

What is claimed and desired to be secured by United States LettersPatent is: v

1. For use in an abrading machine, a rotor having at least one outwardlyextending guideway provided thereon, an abrasive propelling blademounted for sliding movement in said guideway,

and locking means for restraining said bladek against outward movementin response to centrifugal force developed therein through rotation ofsaid rotor, said means comprising a member mounted for sliding guidedmovement in a direction substantially normal to said guideway and beingreleasable to permit said blade to be removed from said guideway, saidlblade having a surface cooperating withsaid locking means and operableto maintain'the latter in locking relationship when said rotor is inoperation.

2. For use in an abrading machine, a rotor abutment face and restrainsaid blade against removal outwardly from said guideway when it isdisposed in a locking position and to allow said blade to be removedoutwardly when it is disposed in a release position, said means beingmounted for guided sliding movement in a direction substantially normalto said guideway, said blade being operable to maintain said means `inblade locking position when said rotor is in'operation.

3. The rotor construction dened in claim 2, wherein the abutment face ofsaid blade is operable to maintain said means in blade-locking positionwhen said rotor is in operation.

4. The rotor construction described in claim 2, wherein said guidewayscomprise a pair of outwardly extending surfaces between which said bladeis disposed, and wherein said means is carried by said rotor anddisposed between said surfaces.

5. For use in an abrading machine, a rotor hav- Il il ing at least oneoutwardly extending guide means provided thereon, an abrasive propelling,blade mounted in said guide means., an elongated member extendingthrough said rotor and having a locking portion, said member beingfreely slidable in a direction substantially normal to said gui'de meansand being movable to bring its locking portion into the path of asurface of said blade wl en said member is rotated about its axis, saidlocking portion of said member being so shaped that when said bladesurface is engaged therewith said member cannot be rotated about itsaxis and is thereby maintained in locking position.

6. For use in an abrading machine, a rotor having at least one outwardlyextending guidewayprovided thereon, an abrasive propelling blade mountedfor sliding movement in said guideway, said blade having at least oneoutwardly facing abutment wall provided thereon, a locking membermounted for freely sliding movement in one direction in said rotor in adirection substantially normal to said guideway and movable into thepath of movement of said blade for restraining the same against outwardmovement in response to centrifugal force, said locking member having aportion adapted for interlocking engagement with said abutment wall ofsaid blade, whereby said blade is operable to restrain said lockingmemberl against turning movement when said rotor is in operation, meansprovided on said blade for preventing said locking member from moving inone direction out of the path of said blade, and means provided on saidmember for preventing it from moving in the other direction out of thepath of said blade.

'7. The rotor construction described in claim 6, wherein the saidportion of said locking member is provided with at least one flat sidewhich cooperates with the abutment wall of said blade.

8. In an abrading apparatus, a rotor having an outwardly extendingguideway provided thereon, an abrasive propelling blade mounted forsliding movement in said guideway, means for restraining said bladeagainst outward movement in said guideway comprising a key memberbridging the outer end of said guideway and providing p an abutment wallagainst which the outer end of said blade is adapted to abut, means forrestraining said key member against outward movement, and means forpreventing said key member from moving out of locking cooperation withsaid blade when said member is engaged with saidA blade.

9. The abrading apparatus described in claim 8, wherein said key memberis mounted for guided sliding movement in a direction normal to saidguideway, and said last-named means is operable to restrain said keymember against sliding movement.

10. The abrading apparatus described in'claim 8, wherein said last-namedmeans comprises a shoulder provided on said blade which is operable toengage said key member.

11. In an abrading apparatus, a rotor having an outwardly extendingguideway provided thereon, an abrasive propelling blade mounted forsliding movement in said guideway, said rotor also having a pair ofinwardly facing abutment walls provided thereon adjacent the outer endof said guideway, said walls being on opposite sides of said guideway,and a key member bridging the open end of said guideway and bearingagainst each of said abutment walls, said key member providing aninwardly facing abutment wall against which said blade is adapted tobear, and means for maintaining said key member in cooperatingrelationshin to said abutmentwalls and said blade.

12. The abrading apparatus described in claim 11, wherein said meanscomprises a pair of abutment faces provided on said rotor andcooperating with opposite ends of said key member.

1 3. 'Ihe abrading apparatus described in claim 11,'- wherein said meanscomprises an abutment face provided on said blade which is operable toengage said key member.

14. In an abrading apparatus, a rotor having a blade mounted forinwardand outward sliding movement thereon, said rotor having a pair ofopen-sided recesses therein, one located each side of said blade, saidrecesses each providing an abutment wall facing toward the center ofrotation of said rotor and an abutment face facing substantially normalto said abutment wall, a key member extending across the outer end ofsaid blade and having portions disposed in said recesses and cooperatingwith said abutment walls and faces, and means for maintaining said keymember in said recesses.

l5. The abrading apparatus described in claim 14, wherein said meanscomprises a shoulder provided on said blade and which is operable toengage behind said key member when said blade is disposed in itsoutermost position.

16. In an abrading apparatus, a rotor of disclike form mounted forrotation and having a blade mounted for inward and outwardly slidingmovement on one face thereof, said rotor having a bore therein disposedin the path of movement of said blade, a bolt member slidably disposedin said bore and operable to restrain said blade against outwardmovement, means provided on said bolt member for preventing movement ofsaid bolt away from said one face of rotor when said bolt member isdisposed in a predetermined angular position in said bore, and means,provided on one end of said bolt vmember and cooperating with saidblade, for preventing said V bolt from moving out of said angularposition.

17. The abrading apparatus described in claim 16, wherein said boltmember is provided with a shoulder for abutting said blade andrestraining said bolt member against movement toward said one face.'

18. In an abrading machine, a rotor mounted for rotation at high speedand having means providing at least one outwardly extending guidewaythereon, an abrasive propelling blade mounted for sliding movement insaid guideway and having an outwardly facing abutment wall, said rotorhaving an opening therein which extends in a direction substantiallyparallel to the axis of rotation of said rotor and substantially no'rmalto said guideway, a locking member having a shank portion mounted forfreely sliding movement in said opening, said member having a headadapted to abut said rotor and adapted to be engaged by the abutmentwall of said blade, for restraining the latter against outward movementin response to centrifugal force.

ERIC O. HAMREN.

